ST. PETERSBURG – Shane McClanahan looked into his locker in the Rays’ clubhouse last week, pointing to a special piece of apparel he planned to pack for the trip to his first career All-Star Game. It was a Dodgers jersey, and above the No. 22 on the back was the last name of McClanahan’s favorite pitcher: Clayton Kershaw.

“That’s somebody I've really watched and idolized and loved the way he's gone about his business,” McClanahan said. Naturally, he was eager to pick Kershaw’s brain at Dodger Stadium but still characteristically reserved when talking about it: “Obviously, I don’t want to fanboy too hard.”

• MLB All-Star Game presented by Mastercard: Tuesday on FOX

One part of Kershaw’s story that’s stuck with McClanahan, though, and still inspires the Rays’ young ace: After winning his second National League Cy Young Award in 2013, Kershaw unveiled a new slider the next year and won both the Cy Young and NL MVP Awards.

“It just shows you're never too good to get better,” McClanahan said.

That attitude is the key to McClanahan’s rapid, four-year evolution from a high Draft pick with admitted “high reliever risk” to the most dominant starting pitcher in baseball throughout the first half of the season and the American League’s starting pitcher in the Midsummer Classic, who will line up against the future Hall of Famer he’s long admired.

“I’m honored,” said McClanahan, who had received more votes in the All-Star player balloting than any other AL starting pitcher. “There are so many deserving guys in the AL who have had a heck of a year so far. To even be in consideration for this was truly just an honor for me. 

“I’d be lying to you if I told you I had never envisioned myself being on that mound competing against the best players in the world. For it to come true is truly an exciting opportunity for me.”

Nobody doubted the hard-throwing left-hander’s natural ability. But what’s set McClanahan apart has been his relentless drive to get better, his awareness to identify potential areas of improvement and his aptitude for quickly putting those changes into practice.

“Once you get complacent, that's when people start passing you by and you start having failure. This game is very hard. It's hard to get here. It's even harder to stay,” McClanahan said. “I think it's ultimately up to the player to kind of push themselves to try and continually get better and improve and become a master of the craft.

“You've just got to have that pursuit of being as good as you can be.”

Eighteen starts into his sophomore season, his first full year in the Majors, it’s hard to find where McClanahan could be any better. The 25-year-old has a 10-3 record, a 1.71 ERA and 147 strikeouts in 110 2/3 innings. He leads the AL, if not the Majors, in nearly every significant statistical category.

And McClanahan's four-pitch arsenal is nearly flawless. His four-seam fastball averages a tick under 97 mph, and he’s added 1 1/2 inches of vertical movement to the pitch this year. Opponents are hitting just .129 with a 31.1 percent whiff rate against his curveball, which is breaking more wickedly than ever. Hitters have missed on nearly half the swings they’ve taken against his slider (46.8 percent) and changeup (45.5). He throws them all just about evenly, and he throws them all for strikes, with a 4.6 percent walk rate that tied for fifth among qualified starters.

That might be what you expect from an All-Star, but it’s not who McClanahan was when he debuted in the 2020 postseason, much less when he was drafted 31st overall out of the University of South Florida in 2018. Back then, he was a sinker-curveball pitcher who, as he puts it, “couldn’t throw strikes.”

“They took a chance on me,” McClanahan said. “I just wanted to make them know it was worth it.”

Senior director of amateur scouting Rob Metzler said the Rays viewed McClanahan as “a talented arm [and] we’ll see where it goes” regarding his future in the rotation or bullpen. McClanahan set out to prove he was a starter, which fueled what Double-A Montgomery manager Morgan Ensberg called “a strong desire to get better and to be in the zone with all of his pitches.”

“The number of different improvements that he has made has been incredible. I think the first thing that comes to mind is his command,” Rays GM Peter Bendix said. “He has gone from somebody who had questionable-at-best command to not just good command, but excellent command. To have command of multiple pitches is something very few pitchers, at any level, have. And to have command of multiple plus pitches is why he's an All-Star.”

McClanahan refined his command enough to stick in the rotation in the Minor Leagues, but his most significant development has taken place in the Majors. He added a slider and tweaked his curveball heading into last season. This year, he’s greatly improved his changeup and, picking up on the way Yankees ace Gerrit Cole pitches, focused on spinning the ball rather than forcing it into the strike zone.

“From a practical application standpoint, he's probably as gifted a guy as I've been around,” Rays pitching coach Kyle Snyder said. “He brings a curiosity to the table, with the ability to apply things at an extremely fast rate, so I think his evolution as a pitcher to this point has had a lot to do with the gift of that. … It's truly remarkable. There's not another word for it. And it's just a testament to his willingness to try things, [and] open his mind to ways to continue to improve.”

What’s next in the All-Star McClanahan’s never-ending journey of self-improvement? Snyder shrugged.

“I'm not too sure that he's not going to approach me about some power knuckleball at some point,” he said, laughing. “He wants to give his team the chance to win every time out -- that's his primary motivation -- and he definitely wants to be the best version of himself that he can be. He's striving to be that every single day.”